The present invention relates to a method for sealing two members and a gasket therefor, in particular, to a method of sealing two engine parts, such as a cylinder head and a cylinder block, and a gasket used for sealing the engine parts.
In sealing two engine parts, such as a cylinder head and a cylinder block for an internal combustion engine, a gasket is generally installed between the two parts. In order to securely seal around a hole to be sealed, such as cylinder bores, water holes and oil holes, the gasket is provided with sealing means around the hole, such as a bead, flange or turning portion, grommet, combination thereof, and so on. When the gasket is tightened, the sealing means provides a surface pressure to securely seal around the hole.
In case the hole to be sealed has an enough space therearound for sealing, though some technical difficulties may be encountered depending on the structure thereof, the hole can be sealed relatively easily by the sealing means. However, if there is no sufficient space around the hole to be sealed, it is difficult to securely seal around the hole.
In case the sufficient sealing space is not obtained or additional sealing means is required, a coating layer containing rubber or resin may be formed on a gasket or between plates for the gasket. The coating layer prevents the fluid from flowing on the gasket or between the plates.
Also, it has been known that a foaming layer may be coated on an entire surface of a gasket. In this case, after the gasket is assembled and the foaming layer is foamed, the gasket with the foamed layer is installed between the engine parts. Therefore, when the gasket with the foamed layer is installed and tightened between the engine parts, the foamed layer may be compressed excessively to loose compressibility or resilience. Even if the foamed layer has compressibility when the gasket is installed between the engine parts, in case the gasket is used for a long time, the gasket is compressed repeatedly. Accordingly, the compressibility of the foamed layer is lost gradually.
The present invention has been made in view of the conventional gasket, and an object of the invention is to provide a gasket with a foamed layer which can provide an adequate surface pressure.
Another object of the invention is to provide a gasket with a foamed layer as stated above, wherein the surface pressure is not substantially lost even if it is used for a long time.
A further object of the invention is to provide a gasket with a foamed layer as stated above, wherein the gasket can provide a surface pressure even in a limited space.
A still further object of the invention is to provide a method for sealing between two members, wherein an adequate surface pressure is formed between the two members and is kept for a long time.
A still further object of the invention is to provide a method as stated above, wherein the adequate surface pressure is formed easily without special treatment.
Further objects and advantages of the invention will be apparent from the following description of the invention.